Guides
The pages on airports, routes and flights are built for looking things up. These four explain how to read them: what a delay statistic counts, where the reasons for delay come from, what each part of an airport page means, and how to use the record when you pick a flight.
How on-time performance is counted
Why a flight 14 minutes late counts as on time, how the US DOT 15-minute rule works, and what happens to cancelled and diverted flights in an on-time rate.
Why flights are delayed: the five DOT causes
The five delay causes US airlines report to the DOT, what “late-arriving aircraft” means, and how the delay minutes were split across 64 major airports.
How to read an airport’s reliability profile
What each section of a FlyerIntel airport page measures, and how to compare two airports fairly given sample sizes, hub airlines and seasons.
Choosing a flight to avoid delays
Practical steps backed by the DOT record: pick the hour first, then the day, then check your own airport, route and connection with the site’s tools.
How the guides are written
Each guide quotes its definitions from the US Department of Transportation rules and the Bureau of Transportation Statistics file the site is built on, and names them at the foot of the page. Every number in the text is read from the same data as the airport pages when the guide is built, with the period stated, so a guide does not keep a figure the data pages no longer show. The standards behind this are in the editorial policy, and every term is defined on the methodology page.